In conventional manner, a fastener member comprises a fastener ring, generally made of plastics material, associated with a covering hoop which can be made of metal or of plastics material. The covering hoop is mounted around the ring in such a manner as to mask it at least in part, thereby advantageously imparting an attractive appearance aspect thereto. In conventional manner, the covering hoop is axially force fitted around the fastener ring, and in principle this friction-clamped contact suffices on its own to secure the hoop on the ring. However, the hoop often turns about the ring, or becomes axially disengaged when very limited force is exerted.
Document FR-2 799 185 provides a partial solution to the problem of fastening the hoop securely on the ring. In that document, the covering hoop is clamped onto the inside of a bushing formed by the ring. Clamping aims to prevent both turning and movement in axial translation. However, even with such internal clamping, the hoop can still turn on the ring. Clamping is more particularly adapted to preventing movement in translation, and apart from a clamping contact, it does not implement specific means for preventing turning.
Document FR-2 779 419, on which the pre-characterizing portion of the main claim is based, describes a pump mounted in a ring which is force-fitted into a reservoir neck. On its outside, the ring forms a groove for engaging with teeth formed inside a cover. The teeth prevent both turning and movement in translation. The teeth are in the form of rectangular studs that project from the inside wall of the cover. However, it is not mentioned clearly how the teeth are held in the groove.